1. Field of Invention
This invention relates in general to domestic, industrial or vehicle internal wiring. More specifically, the invention relates to a molded electrical connector for connecting lead wires to a flat type cable and a method of manufacturing a molded electrical connector.
2. Description of the Prior Art
Typically a connector is used to connect terminals of a printed circuit board to respective conductors of a flat type cable. One arrangement for achieving a good mechanical and electrical connection is to solder the wires to their respective terminals. However, in the case of a printed circuit board installed on a vehicle or the like which may be vibrated during operation, it is difficult to maintain good electrical and mechanical characteristics in the soldered joint for an extended time. Therefore, to achieve higher reliability, it is preferable to spot weld.
FIG. 1 (PRIOR ART) shows a conventional arrangement of connecting lead wires to a flat type cable. In FIG. 1 (PRIOR ART), a flat box-shaped molding 1 includes a plurality of metallic circuits 2. Metallic circuits 2 extend from molding 1 as connecting terminals 3 which are substantially rectangular conductors. A flat type cable 11 includes welding portions 8 and rectangular conductors 12. The metallic circuits 2 are molded in molding 1 in such a manner that they are arranged at predetermined intervals in a plane with the terminals 3 protruding from the molding 1. The molding 1 and the connecting terminals 3 form a molded electrical connector. The connecting terminals 3 and the end portions of the rectangular conductors 12 are fully exposed, can be placed on each other, pressed together with the electrodes of a spot welder from above and below and spot welded. However, it is rather difficult to position the terminals 3 and the rectangular conductors 12. They can easily shift from the desired position before being spot welded.
Employment of a spot welder to weld conductors to the connecting terminals of a molded electrical connector/printed circuit board combination presents an additional problem. Since the connector is formed over the insulating material of the circuit board as described above, no current can flow between the electrodes of the spot welder disposed on both sides of the printed circuit board because of the insulating material thereof.
FIG. 2 (PRIOR ART) shows a conventional molded electrical connector whose connecting terminals 3 are combined with a printed circuit board. In this case, the lower surfaces of the connecting terminals 3 are covered with the insulating material of the printed circuit board. At the positions of the connecting terminals, the upper and lower portions of the circuit board are not conductive. Hence, at these positions, spot welding cannot be performed without means for rendering the upper and lower portions of the circuit board conductive.